8-267 BLACK BUNA 90D BACK-UP RING

APG stocks the HB90267, an AS568-267 black Buna-N (Nitrile) 90 Shore A Back-Up Ring with an inside diameter of 8.234 in (209.14 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 8.512 in (216.2 mm). A back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

As a material, Buna-N (Nitrile) offers low compression set under sustained load, strong abrasion and tear resistance. It resists hydraulic fluids, water, and petroleum-based oils. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C). Verify compatibility before use with strong acids or ketones.

Common environments for this compound include hydraulic and pneumatic systems, fluid power, and agricultural equipment.

This item is sold individually under part number HB90267. Unit weight is approximately 3.0625 g and nominal inside diameter is listed as 8 1/4 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.